process for preparing photo- and heat-sensitive recording material

ABSTRACT

This invention discloses a photo- and heat-sensitive recording material excellent in fixability comprising a support having on one side of which at least one photo- and heat-sensitive layer having a haze % of less than 60 and containing a diazo compound and a coupler, wherein either the diazo compound or the coupler is enclosed in a microcapsule and a process to manufacture it.

FIELD OF THE INVENTION

The present invention relates to a heat-sensitive recording materialexcellent in fixability, and more particularly, to a photo- andheat-sensitive recording material which can be employed as aphoto-sensitive material also.

BACKGROUND OF THE INVENTION

Photo- and heat-sensitive materials having on a support a photo- andheat-sensitive layer containing a diazo compound and a coupler have sofar been known. Specifically, the recording materials of this type usethe combination of a photo decomposable diazo compound, a coupler and aheat fusible substance, and take advantage of the coupling reactionbetween the diazo compound and the coupler, which takes place by heatingto produce a color, and the decomposition of the diazo compound whichtakes place by exposure to light in the photolysis wave length region ofthe diazo compound, and thereby the above-described coloring reaction ishindered to effect the fixation. Therefore, the photo recording can beachieved by imagewise exposing the above-described recording material tolight in the foregoing wave length region, and then heating the materialup to a temperature higher than the melting point of the heat fusiblesubstance. On the other hand, the heat-sensitive recording can beachieved by carrying out the heat recording, and then optically exposingall over the surface of the recording layer. Accordingly, when theabove-described recording material is employed as a heat-sensitiverecording material, the recorded image which has received fixation has amerit that it does not suffer from unnecessary color production in thebackground area, that is, it has excellent keeping quality, which isdifferent from the case of heat-sensitive recording materials of leucodye coloration type.

However, in analogy with the heat-sensitive recording material of leucodye coloration type, the foregoing recording material causes fog duringstorage prior to processings, and so on. That is, it is insufficientmainly in freshness keeping property Therefore, various recordingmaterials have so far been proposed with the intention of improving infreshness keeping property.

Among those recording materials, the recording material proposed by us(in Japanese Patent Application (OPI) No. 65043/83 (the term "OPI" asused herein means an unexamined published application)) is characterizedby enmicrocapsulation of at least one component taking part in acolor-producing reaction, e.g., at least either a diazo compound or acoupler, which involves forming a capsule wall around a core substance,which comprises at least one component participating in thecolor-producing reaction, through polymerization, whereby achieving animprovement in freshness keeping property without attend by lowering ofa recording speed and a color density of developed image.

However, conventional recording materials, including the above-describedrecording material which utilizes enmicrocapsulation, are inferior intransparency. Therefore when images colored in various tints, e.g., red,blue, yellow, etc., are formed therein, the images become darkish, andlack in clearness. In addition, the whiteness in the background area isinsufficient. More specifically, when color images recorded in a photo-and heat-sensitive layer provided on a transparent support are projectedwith an overhead projector (OHP) the conventional photo- andheat-sensitive recording materials suffer from the defects that theprojected background looks darkish, so the contrast is lowered as awhole; and the projected color images look dull, too. Further, whenmulticolor recording is carried out using a photo- and heat-sensitiverecording material in which two or more of photo- and heat-sensitiverecording material in which two or more of photo- and heat-sensitivelayers differing in color of the image to be produced are superposedupon one another, conventional recording materials have a problem thatthey are inferior in the reproducibility of mixed color in everyoverlapped area of images colored in different tints.

Though it is certain that these problems can be solved by the use ofsilver salt color photographic materials, these photographic materialsalso have different problems that they are expensive, and require acomplex and time-consuming photographic processing in forming recordedimages.

SUMMARY OF THE INVENTION

A first object of the present invention is to provide which not onlymakes it feasible to record at such a high speed as commerciallyproduced diazo copying apparatuses and heat-sensitive recording printersare usable therefor, but also is excellent in freshness keepingproperty, color density of recorded image, and record keeping property,and further can record clear images therein at a low price withoutcausing dullness in the background and the color images.

A second object of the present invention is to provide a photo- andheat-sensitive recording material which is excellent in transparency,and can produce such an image as to be projected on a screen in a goodcondition with an overhead projector.

A third object of the present invention is to provide a photo- andheat-sensitive recording material which is excellent in reproducibilityof mixed color arising from overlapping of variously colored records,and therefore, suitable for multi-color recording.

Above objects of the present invention were attained by a photo- andheat-sensitive recording material comprising a support having on oneside of which a photo and heat-sensitive layer containing a diazocompound and a coupler is provided, said photo- and heat-sensitive layerbeing transparent in a substantial sense, and formed by the processwhich comprises enmicrocapsulating either the diazo compound or thecoupler, dissolving the remainder component into an organic solventslightly soluble or insoluble in water, dispersing the resultingsolution in the form of emulsion, mixing the thus obtained microcapsulesolution and emulsified dispersion, coating the resulting mixture on oneside of the support, and then drying the coat. Accordingly, the imagesformed therein enables various kinds of utilization as transmissioncolor images, for instance, color display with an overhead projector.

DETAILED DESCRIPTION OF THE INVENTION

The diazo compounds to be used in the present invention are"photo-decomposable diazo compounds" decomposing on exposure to light ofparticular wavelengths prior to the reaction These diazo compounds aremainly aromatic diazo compounds, including aromatic diazonium salts,diazosulfonate compounds, diazoamino compounds and the like. The diazocompounds are illustrated below citing diazonium salts as typicalexamples.

In general, the wavelength at which diazonium salts undergo photolysisare said to be the wavelengths of their respective absorption maximum.In addition, the absorption maximum wavelength of a diazonium salt isknown to vary between about 200 nm and about 700nm according to itschemical structure(Takahiro Tsunoda & Tsugio Yamaoka, Nippon ShashinGakkaishi, vol. 29(4), pp. 197-205 (1965), the title of which means"photolysis of photo-sensitive diazonium salts and chemical structuresthereof", can be referred to). Namely, when diazonium salts are employedas a photo-decomposable compound, they decompose upon exposure to lightof wavelengths specified depending on their respective chemicalstructures, and the hue of a dye to be produced by coupling reaction canbe varied by using the diazonium salts of a modified chemical structureeven when the same coupling component is used.

The diazonium salts are compounds represented by the general formula ofArN₂ ⁺ X⁻ (wherein Ar represents a substituted or unsubstituted aromaticmoiety, N₂ ⁺ represents a diazonium group, and X⁻ represents an acidanion).

Specific examples of diazonium compounds having their respectivephotolysis wavelengths in the vicinity of 400 nm include4-diazo-1-dimethylaminobenzene, 4-diazo-1-diethylaminobenzene,4-diazo-1-dipropylaminobenzene, 4-diazo-1 - methylbenzylaminobenzene,4-diazo-1 -dibenzylaminobenzene, 4 -diazo-1-ethylhydroxyethylaminobenzene,4-diazo-1-diethylamino-3methoxybenzene,4-diazo-1-dimethylamino-2-methylbenzene,4-diazo-1-benzoylamino-2,5-diethoxybenzene, 4-diazo-1-morpholinobenzene,4 -diazo-1-morpholino-2,5 -diethoxybenzene,4-diazo-1-morpholino-2,5-dibutoxybenzene, 4 diazo-1-anilinobenzene,4-diazo-1-toluylmercapto-2,5-diethoxybenzene, 4-diazo-1,4-methoxybenzoylamino-2,5-diethoxybenzene, and so on. Specificexamples of compounds having their photolysis wavelengths in the rangeof 300 to 370 nm include 1-diazo-4(N,N-dioctylcarbamoyl)benzene,1-diazo-2-octadecyloxybenzene, 1-diazo-4-(4-tert-octyl-phenoxy)benzene,1-diazo-4-(2,4-di-tert-amylphenoxy)benzene,1-diazo-2-(4-tertoctylphenoxy)benzene,1-diazo-5-chloro-2-(4-tertoctylphenoxy)benzene,1-diazo-2,5-bis-octadecyloxybenzene,1-diazo-2,4-bis-octadecyloxybenzene,1-diazo-4-(N-octyltauroylamino)benzene, and so on. Photolysiswavelengths of the aromatic diazonium compounds represented by theabove-cited examples can be changed over a wide range by replacing theirindividual substituent groups by other arbitrary ones.

Specific examples of acid anions include

C_(n) F_(2n+1) COO⁻ (n=an integer of 3 to 9),

C_(m) F_(2m+1) SO₃ ⁻ (m=an integer of 2 to 8),

(C F₂₁₊₁ SO₂)₂ CH⁻ (l=an integer of 1 to 18), ##STR1## PF₆ ³¹ , and soon.

Specific examples of diazonium compounds (idazonium salts) areillustrated below. ##STR2##

Diazosulfonate compounds which can be used in the present invention arethose represented by the following general formula: ##STR3## wherein R₁represents an alkali metal, or an ammonium compound; R₂, R₃, R₅ and R₆each represents a hydrogen atom, a halogen atom, an alkyl group, or analkoxyl group; and R₄ represents a hydrogen atom, a halogen atom, analkyl group, an amino group, a benzoylamido group, a morpholino group, atrimercapto group, or a pyrrolidino group.

Many compounds are known as such diazosulfonates, and can be obtained bytreating the corresponding diazonium salts with a sulfite.

Preferred examples of diazosulfonate compounds includebenzenediazosulfonates having such a substituent group as 2-methoxy,2-phenoxy, 2-methoxy-4-phenoxy, 2,4-dimethoxy, 2-methyl-4-methoxy,2,4-dimethyl, 2,4,6-trimethyl, 4-phenyl, 4-phenoxy, 4-acetoamide, or soon; and benzenediazosulfonates having such a substituent group as4-(N-ethyl-N-benzylamino), 4-(N,N-dimethylamino), 4-(N,N-dimethylamino),4-(N,N-diethylamino)-3-chloro, 4-pyrrolidino-3-chloro,4-morpholino-2-methoxy, 4-(4'-methoxybenzoylamino)-2,5-butoxy,4-(4'-trimercapto)-2,5-dimethoxy, or so on. When these diazosulfonatecompounds are used, it is desired that optical exposure should becarried out before printing for the purpose of activation of thediazosulfonates.

Other diazo compounds which can be used in the present invention arediazoamino compounds. Specific examples thereof include those obtainedby coupling diazo group with dicyandiamide, sarcosine, methyltaurin,N-ethylanthranic acid-5-sulfonic acid, monoethanolamine, diethanolamine,guanidine, etc.

The couplers are compounds which form colors by coupling with diazoniumcompound (diazonium salts).

Specific examples of couplers which can be used include a resorcinol,phloroglucinol, sodium-2,3-dihydroxynaphthalene-6-sulfonate,1-hydroxy-2-naphthoic acid morpholinopropylamide,1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,2,3-dihydroxy-6-sulfanylnaphthalene, 2-hydroxy-3-naphthoic acidmorpholinopropylamide, 2-hydroxy-3-naphthoic acid morpholinopropylamide,2-hydroxy3-naphthoic acid-2'-methylanilide, 2-hydroxy-3-naphthoic acidethanolamide, 2-hydroxy-3-naphthoic acid octylamide,2-hydroxy-3-naphtoic acid-N-dodecyloxy-propylamide,2-hydroxy-3-naphthoic acid tetradecylamide, acetanilide,acetoacetanilide, benzoyl acetanilide, 1-phenyl-3-methyl-5-pyrazolone,1-(2',4 ',6'-trichrorophenyl)-3-benzamide-5-pyrazolone,1-(2',4',6'-trichrorophenyl)-3-anilino-5-pyrazolone,1-phenylacetamide-5-pyrazolone.

By employing two or more of these coupling components, images of anycolor tones can be obtained.

It is desirable to add a basic substance to a recording layer of thepresent invention's photo- and heat-sensitive recording material inorder to accelerate a coupling reaction.

Suitable basic substances include those soluble slightly or insoluble inwater, and substances capable of producing an alkali upon heating.

As examples of such substances, mention may be made of inorganic andorganic ammonium salts, organic amines, amides, urea and thiourea,derivatives of these ureas, thiazoles, pyrroles, pyrimidines,piperazines, guanidines, indoles, imidazoles, imidines, formamidines,pyridines, and other nitrogen containing compounds. More than two basicsubstances may be employed together

In a photo- and heat-sensitive recording material of the presentinvention, a thermocoloring sensitizer such as a hydroxyl compound, acarbamate compound, an aromatic methoxy compound and an organicsulfonamide compound may be added in a photosensitive layer in order tocarry out thermal development completely by a low energy. Thesecompounds seems to lower a melting point of coupling components or abasic substances, or seems to improve a thermopermeability of amicrocapsule wall, therefore, an image density when the photo- andheat-sensitive recording material is used becomes higher.

Among the above mentioned components relating to the coloring reaction,diazo compounds or couplers are enclosed in the microcapsules from viewpoints such as improving transparency of the photo- and heat-sensitivelayer, freshness keeping property by preventing a contact of diazocompounds with couplers at ordinary temperature (fog prevention) andcontrolling a coloring sensitivity to color with desired thermal energyto be added.

Microcapsules preferably employed in the present invention have amicrocapsule wall of such a property as to prevent the contact betweensubstances present inside and outside the microcapsule at ordinarytemperature through its insulation function, but to increase apermeability of the substances only while it is heated to a temperaturehigher than a prescribed one. This phenomenon discovered by uspreviously belongs to new technology. A permeation starting temperaturecan be freely controlled by properly chosing a capsule wall material, acapsule core material, and additives. In this case, the permeationstarting temperature corresponds to the glass transition point of thecapsule wall (as described, e.g., in Japanese Patent Application(OPI)No. 91438/84,Japanese Patent Application Nos. 190886/84 and 99490/84,and so on).

For controlling the intrinsic glass transition point of a capsule wall,it is necessary to change the kind of a capsule wall-forming agent.

Examples of macromolecular substances for capsule wall are apolyurethane, a polyurea, polyamide, polyester, polycarbonate,urea-formaldehyde resin, melamine resin, polystyrene,styrene-methacrylate copolymer, styrene acrylate copolymer, gelatin,poly(vinylpyrrolidone), poly(vinylalcohol), etc. These macromolecularsubstances can be used as a combination of two or more in the presentinvention.

Also, among the above substances, a polyurethane, polyurea, polyamide,polyester or polycarbonate is preferred in this invention. Especially,polyurethane and polyurea are preferable.

As for the microcapsule used in the present invention, it is desirableto manufacture microcapsule by forming a wall of a macromolecularsubstance around the oil drop obtained by emulsifying a core substancecontaining a diazo compounds or couplers.

In this case the reactant to form a macromolecular substance is addedinside and/or outside the oil drop. Details of the microcapsules, whichare used preferably in the present invention, such as a method tomanufacture the microcapsule are described, e.g., in Japanese Patentpublication(OPI) 222716/'86.

An organic solvent to be used for forming oil drop can be properlyselected from those having high boiling points.

Microcapsules can be formed by the use of emulsion containing aningredient to be microencapsulated in a concentration of 0.2 wt % ormore.

It is desirable to use the coupling compound and basic substance inamounts of 0.1 to 10 parts by weight and 0.1 to 20 parts by weight,respectively, per 1 part by weight of the diazo compound.

Desirable microcapsules which are produced in the above-described mannerare not those of the kind which are ruptured by heat or pressure, butthose of the kind which have a microcapsule wall through which reactivesubstances present inside and outside the individual microcapsulesrespectively can permeate at high temperature to react with each other.

In the present invention, a color-producing aid can be used.

A usable color-producing aid is such a substance as to heighten adensity of color produced by heating, or to lower a minimumcolor-production temperature. More specifically, it is used for creatinga condition under which a diazo compound, a basic substance, a couplerand so on can readily undergo reactions with one another through amelting point-lowering action thereof on the diazo compound, etc., or asoftening point-lowering action thereof on the capsule wall.

As examples of color-producing aids which can be used, mention may bemade of phenol compounds, alcoholic compounds, amide compounds,sulfonamide compounds, and so on. Specific examples of these compoundsinclude p-tertoctylphenol, p-benzyloxyphenol, phenyl p-oxybenzoate,benzyl carbanilate, phenetyl carbanilate, hydroquinone dihydroxyethylether, xylylene diol, N-hydroxyethylmethanesulfonic acid amide,N-phenyl-methanesulfonic acid amide, and so on. Such a substance asdescribed above may be incorporated into a core substance, or may beadded to a medium present outside the microcapsules in the form ofemulsified dispersion.

In order to obtain a substantially transparent photo and heat-sensitivelayer in the present invention, a coupler in case of enmicrocapsulatinga diazo compound, or a diazo compound in the reverse case is used in theform of dispersion prepared by dissolving it in an organic solventslightly soluble or insoluble in water, and then mixing with an aqueoussolution containing a surface active agent, and a water-soluble highpolymer as a protective colloid to effect emulsification. In many cases,any component, whether it is a diazo compound or not, may beenmicrocapsulated, or made into an emulsified dispersion. However, it isparticularly preferred that a diazo compound is incorporated intomicrocapsules, while a coupler is chosen as the component for emulsifieddispersion.

An organic solvent to be used for dissolving the color developers can beproperly selected from oils having high boiling point. Preferredexamples of such oils include esters, compounds represented by thefollowing general formula (I) to (IV), triarylmethanes (such astritoluylmethane, toluyldiphenylmethane, and the like), terphenylcompounds (such as terphenyl), alkylated diphenyl ethers (such aspropyldiphenyl ether), hydrogenated terphenyl compounds (such ashexahydroterphenyl), diphenyl ethers, and so on.

Of these oils, esters are particularly preferred in the presentinvention from standpoints of stabilization of emulsified dispersion.##STR4## In the above formula, R¹ represents a hydrogen atom, or analkyl group containing 1 to 18 carbon atoms; R² represents an alkylgroup containing 1 to 18 carbon atoms; and p¹ and q¹ each represents aninteger of 1 to 4, provided that the total number of alkyl groupstherein is 4 or less. Preferred alkyl groups represented by R¹ and R²are those containing 1 to 8 carbon atoms. ##STR5##

In the above formula, R³ represents a hydrogen atom, or an alkyl groupcontaining 1 to 12 carbon atoms; R⁴ represents an alkyl group containing1 to 12 carbon atoms; and n is 1 or 2. p² and q² each represents aninteger of 1 to 4. The total number of alkyl groups is 4 or less in caseof n-1, while it is 6 or less in case of n=2. ##STR6##

In the above formula, R⁵ and R⁶, which may be the same or different,each represents a hydrogen atom, or an alkyl group containing 1 to 18carbon atoms m represents an integer of 1 to 13. r³ and q³ eachrepresents an integer of 1 to 3, provided that the total number of alkylgroups is 3 or less.

Of alkyl groups represented R⁵ and, R⁶, those containing 2 to 4 carbonatoms are particularly preferred.

Specific examples of the compounds represented by the formula (I)include dimethylnaphthalene, diethylnaphthalene, diisopropylnaphthalene,and the like.

Specific examples of the compounds represented by the formula (II)include dimethylbiphenyl, diethylbiphenyl, diisopropylbipheny.,diisobutylbiphenyl, and the like.

Specific examples of the compounds represented by the formula (III)include 1-methyl-1-dimethylphenyl-1-phenylmethane,1-ethyl-1-dimethylphenyl-1-phenylmethane,1-propyl-1-dimethylphenyl-1-phenylmethane, and the like.

Specific examples of esters include phosphates (e.g., triphenylphosphate, tricresyl phosphate, butyl phosphate, octyl phosphate,cresyl-bi-phenyl phosphate), phthalates (e.g., dibutyl phthalate,2-ethylhexyl phthalate, ethyl phthalate, octyl phthalate, buthlbenzylphthalate, tetrahydro dioctyl phthalate, benzoates (e.g., ethylbenzoate,propyl benzoate, butyl benzoate, isopentyl benzoate, benzyl benzoate),abietates(e.g., ethyl abietate, benzyl abietate), dioctyl adipate,isodecyl succinate, dioctyl azelate, oxalates (e.g., dibutyl oxalate,dipentyl oxalate), diethyl malonate, maleates (e.g., dimethyl maleate,diethyl maleate, dibutyl maleate), tributyl citrate, sorbic esters(methyl sorbate, ethyl sorbate, butyl sorbate), sebacic esters (dibutylsebacate, dioctyl sebacate), ethyleneglycol esters (e.g., formic acidmonoesters and diesters, butyric acid monoesters and diesters, lauricacid monoesters and diesters, palmitic acid monoesters and diesters,stearic acid monoesters and diesters, oleic acid monoesters anddiesters), triacetin, diethylcarbonate, diphenylcarbonate,ethylenecarbonate, propylenecarbonate, boric acid esters (e.g., tributylborate, tripentyl borate).Of these esters, it is particularly preferredto use tricresyl phosphate from the standpoint of stabilization ofemulsified dispersion of the color developers.

The above-cited oils can be used as a mixture of two or more thereof, orin combination with other oils.

Further, auxiliary solvents, which have low boiling points and act asdissolution aid, can be added to the foregoing organic solvents in thepresent invention. As examples of particularly preferred auxiliarysolvents, mention may be made of ethyl acetate, isopropyl acetate, butylacetate, methylene chloride, and the like.

Water soluble high polymers to be contained as a protective colloid inan aqueous phase, which is to be mixed with an oily phase wherein colordevelopers are dissolved, can be selected properly from known anionic,nonionic or amphoteric high polymers. Of these high polymers,polyvinylalcohol, gelatin, cellulose derivatives and the like arepreferred.

Surface active agents to be contained additionally in the aqueous phasecan be selected properly from anionic or nonionic surface active agentsof the kind which do not cause any precipitation or condensation byinteraction with the above-described protective colloids. As examples ofsurface active agents which can be preferably used, mention may be madeof sodium alkylbenzenesulfonates (such as sodiumlaurylbenzenesulfonate), sodium dioctylsulfosuccinates, polyalkyleneglycols (such as polyoxyethylene nonylphenyl, ether) and so on.

An emulsified dispersion to be used in the present invention can beprepared with ease by mixing an oil phase containing the above mentionedcomponents and an aqueous phase containing a protective colloid and asurface active agent with a general means for preparing a fine grainemulsion, such as a high-speed stirrer, an ultrasonic disperser or soon, to disperse the former phase into the latter phase.

An oil size (diameter) of the emulsified dispersion is desired to beless than 7 micron to obtain transparent heat sensitive layer having ahaze % value of 60, particularly from 0.1 to 5 micron is preferable.

A value of ratio (weight of oil phase/weight of aqueous phase) isdesired to be from 0.02 to 0.6, especially, from 0.1 to 0.4. If thevalue is less than 0.02, the color developer emulsified dispersionbecomes too diluted one since the aqueous phase becomes too much andsufficient coloring can not be obtained. On the other hand when thevalue becomes larger than 0.6, handling becomes troublesome since aviscosity of the solution becomes high, moreover, the transparency of anobtained heat sensitive layer becomes low.

In preparing the heat sensitive material of the present invention, aproper binder can be used for coating.

Suitable examples of binders which can be used include polyvinylalcohol, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, gum arabic, gelatin, polyvinyl pyrrolidone, casein,styrene-butadiene latex, acrylonitrile-butadiene latex, and variouskinds of emulsions of polyvinylacetate, polyacrylic acid esters,ethylene-vinylacetate copolymer and so on. Such a binder is used at acoverage of 0.5 to 5 g/m² on a solids basis.

In addition to the above-described ingredients, an acid stabilizer, suchas citric acid, tartaric acid, oxalic acid, boric acid, phosphoric acid,pyrophosphoric acid, etc., can be added in this invention.

Images formed in the photo- and heat-sensitive material of the presentinvention can be observed as transmission images or reflection ones fromone side of a transparent support. In the latter case, however, imagesare not clear because of see-through background. Therefore, a whitepigment may be added to the photo- and heat-sensitive layer, or a layercontaining a white pigment may be additionally provided in order to makethe background look white. In both cases, it is effective to apply suchmeans to the outermost layer situated on the side opposite to theobservation side. Suitable examples of white pigments which can be usedinclude talc, calcium carbonate, calcium sulfate, magnesium carbonate,magnesium hydroxide, alumina, synthetic silica, titanium oxide, bariumsulfate, kaolin, calcium silicate, urea resin, and so on.

A size of dispersed particles is preferably 10 microns or less. Apreferred coverage of the photo- and heat-sensitive layer ranges from 3to 20 g/m², particularly from 5 to 15 g/m². When the coverage is below 3g/m², sufficient sensitivity cannot be achieved, while when it is above20 g/m², a further improvement in quality cannot be observed, so thecost is increased in vain.

As for the photo- and heat-sensitive layer of the present invention, atleast one constituent layer must be transparent in a substantial sensein order to bring about an improvement in color separation. Theexpression "transparent in a substantial sense" as used herein means tobe 60 % or less, preferably 50 % or less, and more preferably 30 % orless expressed in terms of Haze (%) (measured with an integrating sphereprocess HTR meter, made by Nippon Seimitsu Kogyo K.K.). On the otherhand, light scattering due to fine unevenness at the surface of thephoto- and heat-sensitive layer has a great influence upon thetransparency of an actual test sample of the photo- and heat-sensitivelayer. Accordingly, when the transparency inherent in the photo- andheat-sensitive layer to be made a subject of discussion in the presentinvention, that is, the transparency inside the photo- andheat-sensitive layer is intended to determine by measurement with a hazemeter, a transparent adhesive tape is applied to the surface of thephoto- and heat-sensitive layer as a simple means to attain the almostcomplete removal of surface scattering. In the above-described manner,the transparency is evaluated.

As for a protective layer which is optionally provided on the photo- andheat-sensitive layer in the present invention, a layer comprising asilicon-denatured polyvinyl alcohol and colloidal silica is favored overothers.

Any type of silicon-denatured polyvinyl alcohol may be used if theycontain silicon atoms in a molecule. However, polyvinyl alcohols inwhich silicon atoms are introduced in such a condition that reactivesubstituent groups, such as an alkoxy group, an acyloxy group, hydroxygroup obtained by hydrolysis or an alkali metal salt thereof, or so on,are attached thereto are preferred.

Methods for synthesizing such denatured polyvinyl alcohols containingsilicon atoms in a molecule are described in detail in Japanese PatentApplication (OPI) No. 193189/83.

Colloidal silica in the present invention is used in the form ofcolloidal solution containing water as dispersion medium, which isprepared by dispersing very fine particles of silicic acid anhydrideinto water. Preferred colloidal silica particles have a size rangingfrom 10 to 100 microns, and a specific gravity of 1.1 to 1.3. The pH ofthe colloidal solution is preferably adjusted to about 4 to 10.

When the foregoing protective layer is provided on the surface of thephoto- and heat-sensitive recording material, the surface scatteringphenomenon is depressed in analogy with the application of thetransparent adhesive tape described above. It is a further surprise tofind that the transparency of the protective layer is very high, and inits turn contributes to a further improvement in transparency of thephoto- and heat-sensitive recording material as a whole. Furthermore,this protective layer can play an additional part of increasing themechanical strength of the photo- and heat-sensitive layer surface whenprovided as the outermost layer, or preventing unnecessary color mixingfrom occurring between lamination layers when provided as an interlayerthere between.

A proper mixing ratio of the silicon-denatured polyvinyl alcohol to thecolloidal silica, in the present invention, is 0.5-3 parts by weightpreferably 1-2 parts by weight of colloidal silica per 1 part by weightof silicon-denatured polyvinyl alcohol. If the amount of the colloidalsilica is less than 0.5 part by weight, it can not bring sufficienteffect for improvement on a transparency, and if it is used in an amountmore than 3 parts by weight a crack occurs in the protective layer whichreduces the transparency.

In the protective layer, more than one other polymers can be usedtogether with above polymer. Some of these polymers are water solublepolymers such as a methylcellulose, a carboxymethylcellulose, ahydroxymethylcellulose, a starchs, a gelatin, a gum arabic, a casein, ahydrolyzed product of styrene-maleic anhydride copolymer, a hydrolyzedhalf-ester product of styrene-maleic anhydride copolymer, apolyvinylalcohol, a modified polyvinylalcohol with carboxyl group, apolyacrylamide derivatives, a polyvinyl pyrrolidone, a polystyrenesodium sulfate, a sodium alginate; styrene-butadiene rubber latex,acrylnitrile-butadiene rubber latex, methylacrylate-butadiene rubberlatex, a water insoluble polymer such as polyvinylacetate emulsion. Apreferred amount to be used together is from 0.01 to 0.5 part by weightper 1 part by weight of silicon-denatured polyvinyl alcohol.

In the protective layer, a pigment, metal soap, wax or cross-linkingagent etc. can be added in order to improve matching of the photo- andheat-sensitive recording material with thermal head when thermalrecording is performed or with heat roller for thermosetting afterphoto-recording.

Some of the pigments are a zinc oxide, a calcium carbonate, a bariumsulfate, a titanium oxide, a lithopone, a talc, an agalmatolite, akaolin, an aluminum hydroxide, an amorphous silica etc., an amount to beadded is 0.005-0.2 times of an amount of total weight of polymerespecially 0.01-0.05 times are preferable. An amount less than 0.005times can not improve the matching of the photo- and heat-sensitiverecording material with thermal head when thermal recording is performedor with heat roller for thermosetting after photo-recording, on theother hand an amount more than 0.2 times reduces both transparency andsensitivity of photo- and heat-sensitive recording material remarkably,which causes damage on commercial value.

Some of the metal soaps are an emulsion of metal salt of higher fattyacid (e.g., a zinc stearate, a calcium stearate, an aluminum stearate)etc., and it's amount to be added is 0.5-20 weight %, preferably 1-10weight % against total weight of the protective layer. Some of the waxesare a paraffion wax, a microcrystalline wax, a carnauba wax, a methylolstearoamide, a polyethylene wax, an emulsion of silicone etc., and anamount thereof to be added is 0.5-40 weight %, preferable 1-20 weight %against total weight of the protective layer.

In a coating solution for the protective layer a surface active agent isadded in order to prepare the protective layer uniforming on the photo-and heat-sensitive layer. Some of the active agents are an alkali metalsalt of sulfosuccinic acid system and an active surface agent containingfluorine atoms etc., concretely they are a sodium salt or an ammoniumsalt etc., of a di-(2-ethylhexyl) sulfosuccinic acid or di-(n-hexyl)sulfosuccinic acid etc.

Other surface active agents or polymer electrolytes can also be added inthe protective layer as an antistatic agent. A preferable amount of theprotective layer to be coated is usually 0.2-5 g/m², particularly 1 g-3g/m² at the solids coverage.

In the photo- and heat-sensitive recording material of the presentinvention, a support such as a paper of a synthesized resin film may beused.

As for the paper to be used as a support, neutralized paper which issized with a neutral sizing agent like an alkylketene dimer and shows pH6-9 upon hot extraction is employed to advantage in the respect oflong-range preservation.

In order to prevent the penetration of a coating composition into paper,and in order to effect a close contact between a thermal head whenthermal recording is performed or heat roller for thermosetting afterphoto-recording and a photo- and heat-sensitive recording layer, paperdescribed in Japanese Patent Application (OPI) No. 116687/82, which ischaracterized by

Stokigt sizing degree/(meter basis weight)² ≧3×10⁻³ and Bekk smoothnessof 90 seconds or more, is used to advantage.

In addition, paper having optical surface roughness of 8 microns or lessand a thicknes of 40 to 75 microns as described in Japanese PatentApplication (OPI) No. 136492/83; paper a density of 0.9 g/cm³ or lessand optical contact rate of 15 % or more, as described in JapanesePatent Application (OPI) No. 69097/83; paper which is prepared from pulphaving received a beating treatment till its freeness has come to 400 ccor more on a basis of Canadian Standard Freeness (JIS P81221) to preventpermeation of a coating composition thereinto, as described in JapanesePatent Application (OPI) No. 69097/83; raw paper made with a Yankeepaper machine, which is to be coated with a coating composition on theglossy side and thereby, improvements on developed color density andresolution are intended, as described in Japanese Patent Application(OPI) No. 65695/83; raw paper which has received a corona dischargeprocessing and thereby, its coating aptitude has been enchanced, asdescribed in Japanese Patent Application (OPI) No. 35985/84; and so oncan be employed in the present invention, and can bring about goodresults. In addition to the above-described papers, all supports whichhave so far been used for general heat sensitive recording papers can beemployed as the support of the present invention.

Nextly, a transparent support employed in the present invention isdescribed.

The transparent support to be used in the present invention includefilms of polyesters such as polyethylene terephthalate, polybutyleneterephthalate and the like, cellulose derivative films like a cellulosetriacetate film, a polystyrene film, polyolefin films such as apolypropylene film or a polyethylene film and the like and so on. Thesefilms may be used, independently or in a laminated form.

A preferred thickness of such a transparent support is within the rangeof 20 to 200 microns, particularly 50 to 100 microns.

A subbing layer may be employed in the present invention to heighten theadhesiveness between the transparent support and the photo- andheat-sensitive layer. As a material for forming the subbing layer,mention may be made of gelatin, synthetic high polymer latexes,nitrocellulose, and so on. A preferred coverage of the subbing layerranges from 0.1 to 2.0 g/m², particularly from 0.2 to 1.0 g/m². When thecoverage is below 0.1 g/m², adhesion of the photo- and heat-sensitivelayer to the support is insufficient, whereas even when it is increasedbeyond 2.0 g/m², the adhesion power attains saturation to bring aboutonly increase in cost.

It is to be desired that the subbing layer should be hardened with ahardener because it sometimes swells by water contained in the photo-and heat-sensitive layer coated thereon.

As examples of hardeners which can be used in the present invention,mention may be made of:

(1) active vinyl-containing compounds, such as divinylsulfone,N,N'-ethylenebis(vinylsulfonylacetamide),1,3-bis(vinylsulfonyl)-2-propanol, methylenebismaleimide,5acetyl-1,3-diacryloyl-hexahydro-s-triazine,1,3,5-triacryloyl-hexahydro-s-triazine,1,3,5-trivinylsulfonylhexahydro-s-triazine, and the like,

(2) active halogen-containing compounds, such as sodium salt of2,4-dichloro-6-hydroxy-s-triazine, 2,4-dichloro-6-methoxy-s-triazine,sodium salt of 2,4-dichloro-6(4-sulfoanilino)-s-triazine,2,4-dichloro-6(2-sulfoethylamino)-s-triazine,N,N'-bis(2-chloroethylcarbamyl)piperazine, and the like,

(3) epoxy compounds, such asbis(2,3-epoxypropyl)methylpropylammonium-p-toluenesulfonate,1,4-bis(2',3'-epoxypropyloxy)-butane, 1,3,5-triglycidylisocyanurate,1,3-diglycidyl-5-(γ-acetoxy-β-oxypropyl)isocyanurate, and the like.

(4) ethyleneimino compounds such as 2,4,6-triethylene-s-triazine,1.6-hexamethylene-N,N'-bisethyleneurea,bis-β-ethylenemininoethylthioether, and the like,

(5) methanesulfonate compounds, such as 1,2-di(methane-sulfonoxy)ethane,1,4-di(methanesulfonoxy)butane, 1,5-di(methanesulfonoxy)pentane, and thelike,

(6) carbodiimide compounds, such as dicyclohexylcarbodimide,1-cyclohexyl-3(3-trimethylamino-propyl)carbodiimido-p-triethanesulfonate,1ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and thelike,

(7) isooxazole compounds, such as 2,5-dimethylisooxazole perchlorate,2-ethyl-5phenylisooxazole-3sulfonate, 5,5'-(p-phenylene)bisisooxazole,and the like,

(8) inorganic compounds, such as chrome alum, bolic acid, zirconiumsalt, chromium acetate, and the like,

(9) dehydrating condensation type peptide reagents such asN-carboethoxy-2-isopropoxy-1,2-dihydroquinoline,N-(1-morpholinocarboxy)-4-methylpyridinium chloride and the like, andactive ester compounds such as N,N'-adipoiyldioxydisuccinimide,N,N'-terephthaloyl-dioxy-disuccinimide and the like, and

(10) isocyanates, such as toluene-2,4-diisocyanate,1,6-hexamethylenediisocyante and the like.

(11) aldehydes such as glutaric aldehyde, glyoxal, dimethoxy urea,2,3-dihydroxy-1,4dioxane and the like.

Among these hardeners, especially aldehydes such as glutaric aldehyde,or 2,3-dihydroxy-1,4-dioxane, and boric acid are preferable.

Such a hardner is added in a proportion ranging from 0.20 to 3.0 wt% tothe weight of the materials to constitute the subbing layer. A properamount to be added can be selected depending on the coating method, theintended degree of hardening.

When the addition amount of a hardener is below 0.20 wt%, sufficienthardening can not be achieved however long the time elapsed is, andtherefore the subbing layer swells upon coating of the photo-sensitivelayer, whereas when the hardener is added in a concentration higher than3.0 wt% the hardening proceeds too fast, and therefore the adhesivenessbetween the subbing layer and the support is lowered to result inpeeling off the subbing layer from the support.

According to the hardener used, the pH of a coating solution for thesubbing layer can be rendered alkaline by the addition of sodiumhydroxide or the like, or acidic by the addition of citric acid or thelike, if needed.

Further, a defoaming agent can be added in order to eliminate foamsgenerated upon coating, and a surface active agent can also be added inorder to level the surface of the coating solution in a good conditionto result in prevention of coating streaks.

Furthermore, an antistatic agent can be added, if needed.

Before coating of the subbing layer, the surface of a support ispreferably subjected to an activation processing according to knownmethods. As a method for the activation processing, mention may be madeof an etching processing with an acid, a flame processing with a gasburner, a cornea discharge processing, glow discharge processing, and soon. From the viewpoint of cost or simplicity, corona dischargeprocessing described in U.S. Pat. Nos. 2,715,075, 2,846,727, 3,549,406and 3,590,107, and so on are employed to the greatest advantage.

The photo-and heat-sensitive recording material is fundamentallycomprised of a support having above mentioned essentially transparentphoto- and heat-sensitive layer on one side thereof. Therefore, variousembodiments are able to realize the present invention according to a useand a purpose: e.g. a recording material comprised of a support havingdirectly thereon more than two photo- and heat-sensitive layers coloringin different hue each other, wherein, protectiver layer or subbing layermay be provided optionally; a recording material comprised of supporthaving thereon a known layer selected from a group consisting of photosensitive layer, heat sensitive layer and photo- and heat-sensitivelayer, and further a substantially transparent photo-and heat-sensitivelayer explained in the specification, wherein the latter layer colors indifferent hue to the former layer.

Coating compositions prepared in accordance with the present inventionare coated using a dip coating process, an air knife coating process, acurtain coating process, a roller coating process, a doctor coatingprocess, a wire bar coating process, a slide coating process, a gravurecoating process, an extrusion coating process, using a hopper describedin U.S. Pat. No. 2,681,294, or so on. Two or more of different coatingcompositions can be coated simultaneously, if desired, using methodsdescribed in U.S. Pat. Nos. 2,761,791, 3,508,947, 2,941,898 and3,526,528, Yuji Harasaki, Coating Kogaku (which means "CoatingEngineering"), p. 253, Asakura Shoten (1973), and so on. An appropriatemethod can be chosen from the above-cited ones depending on intendedcoverage, coating speed, and so on.

In the coating compositions of the present invention, it is allowed tocompound properly a pigment dispersing agent, a viscosity increasingagent, a fluidity modifying agent, a deforming agent, a foam inhibitor,a mold lubricant, a coloring agent and so on far as they have no adverseinfluences upon characteristics.

In the photo- and heat-sensitive recording material of the presentinvention, images excellent in fixability can be recorded by a processcomprising the step of carrying out duplication by imagewise exposure tolight in photolysis wave length region of photo-decomposable diazocompounds, or photo recording by point exposure utilizing a light valve,such as a liquid crystal light valve, etc., and uniformly heating thephoto- and heat-sensitive layer with a hot roller up to a temperaturehigher than a heat fusion temperature of the heat sensitive materialincluding microcapsules to result in color development; or by the otherprocess comprising the steps of carrying out heat recording with athermal head, and through exposure to light in the above-described wavelength region. As for the light source for photolysis, various lightsources which can emit light of desired wavelengths can be used. Forexample, various types of fluorescent lamps, a xenon lamp, a xenon flashlamp, mercury lamps in which mercury vapor is enclosed at variouspressures, a photographic flash, Strobe, etc., can be employed as lightsource. To make an additional remark, a light source part and a lightexposure part may be separated with an optical fiber.

The photo- and heat-sensitive recording material of the presentinvention not only demonstrates high sensitivity to light uponduplication by imagewise exposure or photo printing, and can bedeveloped or fixed when heated at a constant temperature, but also hasheat sensitivity high enough to achieve the low temperature high-speedheat recording, and can be fixed in a short time using a light source ofcomparatively low power. Therefore, it can be suitably used for varioustypes of heat-sensitive recording and photo-sensitive recording.

Further, the photo- and heat-sensitive recording material of the presentinvention is excellent in transparency, and can provide recorded colorimages excellent in transparency by heat-sensitive recording andphoto-sensitive recording.

Furthermore, the photo- and heat-sensitive recording material of thepresent invention can produce recorded images which have hightransparency in both background and color-image areas, so it candemonstrate excellent reproducibility of mixed color when transparentcolor images are overlapped. That is, the recording material of thepresent invention can be suitably used for multicolor recording.

EXAMPLES

The present invention will now be illustrated in more detail byreference to the following examples. However, the present inventionshould not be construed as being limited to these examples.

Additionally, in the following examples, all parts are by weight unlessotherwise indicated.

Example 1.

Preparation of Capsule Solution (A):

Diazo Compound illustrated below

    ______________________________________                                         ##STR7##                  3.4 parts                                          Tricresyl Phosphate        6 parts                                            Methylene Chloride         12 parts                                           Trimethylolpropane Trimethacrylate                                                                       18 parts                                           Takenate D-110N(75 wt % ethyl acetate                                                                    24 parts                                           solution, produced by TAKEDA YAKUHIN                                          KOGYO K.K.)                                                                   ______________________________________                                    

The above-described ingredients were mixed, and added to a watersolution prepared by mixing 63 parts of a 8 wt% water solution ofpolyvinyl alcohol and 100 parts of distilled water. The resultingmixture was converted to an emulsion having a mean particle size of 2microns by a dispersion treatment at 20° C. The stirring of the emulsionwas allowed to continue for 3 hours at 40° C.

Thereafter, the emulsion was cooled at 20° C. and thereto was added 100cc of Amberlite IR-120B (trade name, product of Rohm & Haas Co.). Themixture was stirred for one hour, then passed through a filter. Thus,the capsule solution (A) was obtained.

Preparation of Coupler/Base Dispersion (A) (Emulsion)

(I). 4g wt% Water Solution of Polyvinyl Alcohol 170 parts

(II). Coupler illustrated below

    ______________________________________                                         ##STR8##                 1.4 parts                                           Triphenylguanidine (base) 6 parts                                             color-producing assistant                                                      ##STR9##                 12.5 parts                                          and                                                                            ##STR10##                1.5 parts                                           Tricressyl phosphate      10 parts                                            Ethyl acetate             20 parts                                            ______________________________________                                    

The solution (II) was added into the solution (I), then emulsified at 20C to obtain dispersed emulsion having a mean particle size of 3 microns.

Preparation of Coating Composition (A)

    ______________________________________                                        Capsule Solution (A)   4.9 parts                                              Hydroqunone 5 wt % aqueous solution                                                                  0.2 parts                                              Coupler/Base Dispersion (A)                                                                          3.7 parts                                              ______________________________________                                         Above components were mixed with agitation to prepair coating solution        (A).                                                                     

Preparation of Coating Composition for Protective Layer

    ______________________________________                                        silicon-denatured Polyvinyl alcohol                                                                    1 part                                               (PVA R2105: manufactured by Kurare K.K.)                                                              (solid base)                                          Colloidal Silica        1.5 parts                                             (Snowtex 30: manufactured by                                                                          (solid base)                                          Nissan Kagaku K.K.)                                                           ______________________________________                                    

    ______________________________________                                        Zinc Stearate       0.02 parts                                                (Hydrin Z-7: manufactured by                                                                      (solid base)                                              Chukyo Yushi K.K.)                                                            Paraffine Wax       0.02 parts                                                (Hydrin P-7: manufactured by                                                                      (solid base)                                              Chukyo Yushi K.K.)                                                            ______________________________________                                    

Coating for Production of Recording Sheet

On a 75micron-thick transparentpolyethylene terephthalate film thecoating composition for a protective layer was coated and dried to formthe protective layer of a dry coverage of 2 g/m². On the protectivelayer, the coating composition (A) was coated and dried to form thephoto- and heat-sensitive layer of a dry coverage of 12 g/m². Thus, aphoto- and heat-sensitive recording material was obtained.

A haze transmittance of the thus obtained photo- and heat-sensitiverecording material was measured with an integrating sphere process HTRmeter made by Nippon eimitsu Kogyo K.K.. In addition, the transparencyof this material was ascertained by observing with naked eyes.

The results obtained are shown in Table 1.

Then, the photo- and heat-sensitive recording material was printed witha Hitachi Hi-Fax 400 to result in yellow coloration.

Thereafter, the recording material was exposed to light for 10 secondswith a Ricopy Superdry 100, and heated again at 120 C for 5 seconds witha hot block. However, re-coloration did not take place. Thus, the yellowimage excellent in fixability was obtained.

On the other hand, an transmissible original was superposed on thesurface of the photo- and heat-sensitive layer of the recordingmaterial, exposed to light for 10 seconds with a Ricopy Superdry 100,and then heated for 1 second with a 120 C hot block, resulting in theformation of a clear positive yellow image.

Next, the image-recorded materials obtained by the foregoing recordingprocesses, respectively, were placed on an overhead projector, and therecorded images were projected on a screen. The projected images eachwas clear transparent yellow image, and no stain was observed in thebackground area.

EXAMPLE 2

Another photo- and heat sensitive recording material was produced in thesame manner as in Example 1, except the following coupler was used inplace of the coupler used in Example 1: ##STR11##

The transparency of the thus obtained photo- and heat-sensitiverecording material was evaluated by the same method as in Example 1. Theresults obtained are shown in Table 1, too.

Heat-sensitive recording was performed using this recording material inthe same manner as in Example 1, and thereby a magenta image excellentin fixability was obtained.

On the other hand, photo-sensitive recording was also performed usingthis photo- and heat-sensitive recording material in the same manner asin Example 1, resulting in the formation of clear positive magentaimage.

Then, the image-recorded materials obtained by the foregoing recordingprocesses, respectively, were placed on an overhead projector, and therecorded images were projected on a screen. The projected images eachwas clear transparent magenta image, and no stain was observed in thebackground area.

EXAMPLE 3

The recorded images obtained in Example 1 and Example 2 by the foregoingheat-sensitive or photo-sensitive recording process were superposed uponeach other, and the color of the part where the two colors overlappedeach other was observed by the naked eye. Therein, turbidnessfree, clearorange color was observed.

COMPARATIVE EXAMPLE 1

Preparation of Coupler/Base Dispersion B

The same coupler, base, and polyvinyl alcohol solution as contained inthe coupler/base dispersion A were mixed and dispersed with a Dyno Mill(trade name, produced by Willy A Bachofen A.G(trade name)) to obtain adispersion having a mean particle diameter of 3 microns, which differedfrom the coupler/base dispersion A in the absence of the tricresylphosphate and ethyl acetate.

Preparation of Color-Producing Aid Dispersion B

    ______________________________________                                        Color-producing Aids                                                          ______________________________________                                         ##STR12##                  25 parts                                          and                                                                            ##STR13##                  3 parts                                           4 wt % Aqueous Solution of Polyvinyl Alcohol                                                              138 parts                                         ______________________________________                                    

The above-described ingredients were mixed and dispersed with a Dynomill to obtain a dispersion having a mean particle diameter of 3microns.

Preparation of Coating Composition B

The coating composition B was prepared in the same manner as the coatingcomposition A, except 3.7 parts of the coupler/base dispersion A and 3.7parts of the color-producing aid dispersion B were used in place of thecoupler/base dispersion A.

Coating for Production of Recording Sheet

A photo- and heat-sensitive recording material for comparison wasproduced in the same manner as in Example 1, except the coatingcomposition B was used in place of the coating composition A.

The transparency of this photo- and heat-sensitive recording materialwas evaluated by the same method as in Example 1.

                  TABLE 1                                                         ______________________________________                                        Kind of Photo- and Heat-                                                      Sensitive Material                                                                            Haze Transmittance                                                                          Transparency                                    ______________________________________                                        Example 1       12 (%)        good                                            Example 2       12 (%)        good                                            Comparative Example 1                                                                         87 (%)        bad                                             ______________________________________                                    

What is claimed is:
 1. A process to prepare a photo- and heat-sensitiverecording material excellent in fixability consisting essentially of asupport having on one side thereon at least one photo- andheat-sensitive layer having a haze % of less than 30 containing aphoto-decomposable diazo compound and a coupler, said coupler being acompound which forms color by coupling with the diazo compound,comprising microencapsulating either the diazo compound or the couplerwherein the component to be microencapsulated is present in aconcentration of 0.2 wt% or more, dissolving the remainder componentinto a high boiling point organic solvent slightly soluble or insolublein water, dispersing the resulting solution containing the remaindercomponent in an aqueous solution to form an emulsified dispersion havingan oil size diameter of less than 7 microns and an oil phase/aqueousphase weight ratio of from 0.02 to 0.6, mixing the thus obtainedmicrocapsule solution and emulsified dispersion, coating the resultantmixture on one side of the support, then drying the coat.
 2. The processas claimed in claim 1, wherein said organic solvent which is slightlysoluble or insoluble in water is an ester compound.